Federal prosecutors called the Jerseyville woman a danger to the community and herself.

Authorities allege that Smith left a letter in a restroom at Calhoun County High School in Hardin, about 40 miles northwest of St. Louis. Investigators say the April 28 note warned “this school is going down today. KABOOM!”

Smith was arrested the next day. She’s been placed on paid administrative leave.

A message left Tuesday with her public defender, Phillip Kavanaugh III, was not immediately returned.